Mericle Commercial Real Estate Services plans to prepare more than 90 sites and build dozens of speculative commercial buildings on about 1,700 acres it owns in 10 business parks in the two counties, Mericle spokesman Jim Cummings said Thursday.

Mr. Cummings said the investment, which will cost hundreds of millions of dollars, is part of a new initiative called “Ready to Go” that will market the prepared sites for possible manufacturing, distribution, office and medical jobs. The project represents about a decade of work, he said.

The sites range from 1.15 acres to 125 acres and can accommodate companies needing buildings from less than 5,000 square feet to more than 1.4 million square feet. Filling the space will depend on the economy, Mr. Cummings said.